Comparison of unstructured grid and overset grid approaches for flow computations around a ship with an energy-saving duct

Two approaches for CFD simulations for a complex geometry of a ship with an energy-saving duct are compared. One method is an unstructured grid method in which the single block grid can cover the whole geometry and the other is an overset grid method which uses multiple grid blocks for each component of the complex geometry. The computed results are compared with each other and with the experimental data for the resistance and the self-propulsion factors together with the flow fields. Based on these comparisons, two approaches are assessed from the practical point of view